In the topological method, we generalise the above concepts by introducing the notion of walk-matrix.
For the entries in a walk-matrix, we don't necessarily use trees of self-avoiding walks. We may use other
topological constructions of \(G\)  such as path-trees, universal covers etc (see
more about these constructions in the excellent textbook [1]}). Also, we have weights on
the paths of this construction. The weight of each path can be chosen arbitrarily, i.e., it is
not necessarily an influence. Each entry in the walk-matrix is a sum of weights of appropriately chosen paths
in the topological construction. In that respect, one might regard the influence matrix \({{\mathcal {I}}}^{\Lambda ,\tau }_{G}\) 
to be a special case of walk-matrix (e.g. see Lemma REF ).
